Wind turbine rotor blade

Abstract

A rotor blade for addressing the deflection of rotor blades of a wind turbine. The rotor blade includes a plurality of exterior surfaces defining a blade body having a pressure side, a suction side, a leading edge and a trailing edge. The blade body extending between a blade tip and a blade root. The blade body including a breakaway tip portion defined by a predetermined breaking point. The breakaway tip portion is configured to break away from the remaining portion of the blade body when subject to a predetermined tower strike load. A wind turbine including the rotor blade configuration is further disclosed.

The invention claimed is: 
     
       1. A wind turbine rotor blade comprising:
 a plurality of exterior surfaces defining a blade body having a pressure side, a suction side, a leading edge and a trailing edge, the blade body extending between a blade tip and a blade root, the rotor blade defining a span and a chord, and 
 the blade body including a breakaway tip portion and a predetermined breaking point, the predetermined breaking point defined by a banding of material having a reduced strength margin from that of a material forming a remainder of the blade body, 
 wherein the breakaway tip portion is configured to break away at the predetermined breaking point upon deflection of the blade body resulting in an impact of the breakaway tip portion with a tower. 
 
     
     
       2. A wind turbine rotor blade as claimed in  claim 1 , wherein the blade body is comprised of a number of material plies, and wherein the predetermined breaking point is defined by an area comprised of a lesser number of material plies than the number of material plies defining the remaining portion of the blade body. 
     
     
       3. A wind turbine rotor blade as claimed in  claim 1 , wherein the breakaway tip portion is comprised of a material configured for shattering when subject to deflection of the blade body resulting in the impact of the breakaway tip portion with the tower. 
     
     
       4. A wind turbine rotor blade as claimed in  claim 1 , wherein the breakaway tip portion is comprised of an impact load limiting material configured to break away when subject to deflection of the blade body resulting in the impact of the breakaway tip portion with the tower. 
     
     
       5. A wind turbine rotor blade as claimed in  claim 1 , wherein the breakaway tip portion comprises a load carrying structural component including a weakened portion at the predetermined breaking point to provide breaking away of the breakaway tip portion when subject to deflection of the blade body resulting in the impact of the breakaway tip portion with the tower. 
     
     
       6. A wind turbine rotor blade as claimed in  claim 5 , wherein the load carrying structural component comprises at least one of a spar cap or a web. 
     
     
       7. A wind turbine rotor blade as claimed in  claim 5 , wherein the load carrying structural component comprises a bolt. 
     
     
       8. A wind turbine rotor blade as claimed in  claim 5 , wherein the weakened portion at a predetermined breaking point is defined by one or more perforations formed in the load carrying structural component. 
     
     
       9. A wind turbine rotor blade as claimed in  claim 5 , wherein the weakened portion at a predetermined breaking point is defined by a narrowing in geometry of the load carrying structural component. 
     
     
       10. A wind turbine rotor blade as claimed in  claim 1 , wherein the predetermined breaking point is defined by a weakened material. 
     
     
       11. A wind turbine rotor blades as claimed in  claim 10 , wherein the weakened material includes fewer material plies than the remaining portion of the rotor blade. 
     
     
       12. A wind turbine rotor blade as claimed in  claim 1 , wherein the predetermined breaking point is defined by one or more perforations formed through at least a portion of the rotor blade structure. 
     
     
       13. A wind turbine rotor blade as claimed in  claim 1 , wherein the rotor blade is a jointed blade. 
     
     
       14. A wind turbine, the wind turbine comprising a plurality of rotor blade assemblies, at least one of the rotor blade assemblies comprising:
 a suction side surface and a pressure side surface, and defining a span and a chord, the suction side surface and the pressure side surface defining a blade body extending between a blade tip and a blade root, 
 the blade body including a breakaway tip portion and a predetermined breaking point defining a point at which the breakaway tip portion may break away, the predetermined breaking point defined by a banding of material having a reduced strength margin from that of a material forming the blade tip and a remaining portion of the blade body, 
 wherein the breakaway tip portion is configured to break away at the predetermined breaking point upon deflection of the blade body resulting in an impact of the breakaway tip portion with a tower. 
 
     
     
       15. A wind turbine claimed in  claim 14 , wherein the breakaway tip portion is comprised of an impact load limiting material configured to break away when subject to deflection of the blade body resulting in the impact of the breakaway tip portion with the tower. 
     
     
       16. A wind turbine as claimed in  claim 14 , wherein the breakaway tip portion comprises a load carrying structural component, including a weakened portion at the predetermined breaking point, configured to breakaway when subject to deflection of the blade body resulting in the impact of the breakaway tip portion with the tower. 
     
     
       17. A wind turbine as claimed in  claim 16 , wherein the weakened portion at the predetermined breaking point is defined by at least one of one or more perforations in the load carrying structural component or a narrowing in geometry of the load carrying structural component. 
     
     
       18. A wind turbine as claimed in  claim 14 , wherein the predetermined breaking point is defined by a weakened material. 
     
     
       19. A wind turbine as claimed in  claim 14 , wherein the predetermined breaking point is defined by one or more perforations formed through at least a portion of the rotor blade body. 
     
     
       20. A wind turbine comprising:
 a tower; 
 a hub; and 
 at least one rotor blade rotatably connected to the hub, the at least one rotor blade rotatable in response to wind impinging upon the at least one rotor blade, the rotor blade comprising:
 a suction side surface and a pressure side surface, and defining a span and a chord, the suction side surface and the pressure side surface defining a blade body extending between a blade tip and a blade root, 
 the blade body including a breakaway tip portion and a predetermined breaking point defined by a banding of material having a reduced strength margin from that of a material forming a remainder of the blade body, wherein the breakaway tip portion is configured to break away at the predetermined breaking point upon deflection of the blade body resulting in an impact of the breakaway tip portion with the tower. 
 
 
     
     
       21. A wind turbine claimed in  claim 20 , wherein the breakaway tip portion is comprised of one of an impact load limiting material configured to break away when subject to the predetermined load condition or a load carrying structural component including a weakened portion at the predetermined breaking point to provide for breaking away of the breakaway tip portion when subject to deflection of the blade body resulting in the impact of the breakaway tip portion with the tower. 
     
     
       22. A wind turbine as claimed in  claim 20 , wherein the predetermined breaking point is defined by one of a weakened material portion or one or more perforations formed through at least a portion of the rotor blade body.